Crystallization and Preliminary X-Ray Analysis of the Low-Affinity Complex Between Human Leukocyte Antigen-G (HLA-G) and Leukocyte Ig- Like Receptor B2 (LILRB2)

Title: Crystallization and Preliminary X-Ray Analysis of the Low-Affinity Complex Between Human Leukocyte Antigen-G (HLA-G) and Leukocyte Ig- Like Receptor B2 (LILRB2)

Volume: 16 Issue: 4

Author(s): Mitsunori Shiroishi and Katsumi Maenaka

Affiliation:

Keywords: HLA-G, leukocyte Ig-like receptor, immune suppression, crystallization, dehydration, low-affinity complex

Abstract: Human leukocyte antigen-G (HLA-G) is a nonclassical MHC class I (MHCI) molecule that is expressed mainly on placenta trophoblast cells. Leukocyte Ig-like receptor B2 (LILRB2) is a human inhibitory immune receptor that recognizes HLA-G with a higher affinity than any other MHCI although this interaction is only in the µM range. The interaction between HLA-G and LILRB2 seems to play a dominant role in the escape of the fetus from the maternal immune response. Here we report the crystallization and x-ray analysis of the LILRB2/HLA-G complex. The extracellular domains of HLA-G and LILRB2 were expressed in Escherichia coli, refolded and purified. The initial crystallization trials using novel PEG-based screening sets provided crystals of the LILRB2/HLA-G complex with 40-50% PEG400 as the precipitant. These crystals belong to space group P3121 (a=b=81.4 Å, c=186.7 Å, γ=120°). Dehydration of the crystals by soaking them in a solution containing a higher concentration of PEG400 dramatically improved the resolution and also the mosaicity.

Cite this article as:

Shiroishi Mitsunori and Maenaka Katsumi, Crystallization and Preliminary X-Ray Analysis of the Low-Affinity Complex Between Human Leukocyte Antigen-G (HLA-G) and Leukocyte Ig- Like Receptor B2 (LILRB2), Protein & Peptide Letters 2009; 16 (4) . https://dx.doi.org/10.2174/092986609787848108

DOI https://dx.doi.org/10.2174/092986609787848108	Print ISSN 0929-8665
Publisher Name Bentham Science Publisher	Online ISSN 1875-5305